Air-swept ball mim



` oct. 15, 1929."

H. H. WATERMAN AIR swEPT BALL MILL Re. 17,4762v original Filed Nov". 25,' 1924l 2 simil-5h01 1 /3 I "f-'TOR/HRRY fl. MTE/iwan oci. 15', 1929. .H' H`W^TERM^N R@ 17,462l

AIR SWEET BALL MILL 1` Original'Fled Nov. 25, 1924 25Min-Shut 2 y Shaw/14h66 @Y q m, mz, E( am. u H .w f @N QM N WN scisma oa. is', 1929 i UNITED STATES Piifrsrri- OFFICE mara. wnrnniiia'n, or sfrmisnune simenon, vxncmrray AIB-SWEPT BALL MILL V@riginal No. 1,080,992, (lated Hay 81, 1927, Serial No. 752,133, nled November 1924. Application for reissue led August 2.8, 1929. Serial-No. 389,769.

pulverizing, and separating cement clinkers.,

and pulverized coa The impalpable dust 15 ory finished product of the mill is collected,

stored' in bins, or otherwise handled for future use in the arts and trades.

While I shall hereinafter refer to cement elinkers as the material treated it will be 4gf, understood that the apparatus o my invention is equally Well adapted for reducing or pulverizing, separating, and collecting lighter or finer materials from phos hate rock and such other materials from which it gais desired to separate the dust.

` .In connection with the air swept ball mill I utilize a continuous circulation ofpair currents for holding in suspension, separating, and collecting the comminuted material, and

arriinge a fan blower in the system for creating and maintaining this circulation, said fan blower being disposed in compact rela- Vtion with the operating parts ofthe mill or separator. Means are provided in the air cir- -fculation system for regulating the velocity and pressure of air in the supply pipe relative tothe capacity of the intake of the fan or blower, and this regulation `is accom lished by means-of variations in the sizeso pipes,

and also b the assistance of an auxiliary co1- lector wit inthe system.

The invention consists in certain novel combinations and arrangements of parts involving the utilization ofthe air swept ball mill orreducing mechanism in combination witlr the air circulating system as will hereinafter be more fully pointed out and claimed.

In the accompanying drawings I have illustrated one complete example of the physical embodiment of my invention wherein the parts are combined and arranged according to the best inode I Vhave thus far devised for the practical application of the principles of my invention. Before proceeding with the description in detail of my invention, it will be proper to say that in some or all respects my invention. is applicable for various uses,

and I 'therefore do not confine myself to thev excinpliiication herein shown and described.

Figure 1 is a view in elevation showing an installation of my system for pulverizing, separating and collecting the reduced material.

Figure 2 is an enlarged vertical longitudinal sectional view through the mill.

Figure 3 is an enlarged transverse sectional view at line 3--3 of Figure 2.

In carrying out my invention I utilize a rotary drum orcylindrical casing 1 preferably fashioned of cast iron and equipped in such manner as to insure durability and satisfactory results Whether used for light Work or under severe conditions. The drinn is designed for use with various sizes of balls or grinding mediums, the latter as indicated in Figure 2 beingv steel balls 2, 3 and 4 used in suitable numbers for grinding and pulverizing the material as it passes through the drum.

Three compartments (or a larger or smaller number) 5, 6, and 7 are provided within the drum, the coarsest material being suppliedV to the first compartment 5 and ground therein. The material is supplied to the drum by means of a conveyor, as a screw 8 located in a trough 9 at the bottom of the charging or feeding head 10 which receives the material by gravity through a feed pipe 11 from .the feed hopper or bin 12, located and supported in suitable position for the purpose. The drum is supported to rotate upon its axis in usual manner as by pairs of supporting rollers 13 and annular tracks 14, and the drum may be equipped with any suitable operating mechanism as an exterior annular rack ring 15 and pinion 16 on shaft 17, and power is supplied to a driving. pulley 18 on the shaft 17 A. sprocket 18 is indicated as part of mechanism for coupling the drivingeearing.'

The rotary drum is provided with. closed substantially air tight and dust proof heads at the charging and discharging ends. In Figures l and 2 I have shown at the charging end ot the drum a flange 19 which is bolted to a flanged, annularI endv plate 2O closing a portion of the drum at its charging end, and this 4 end plate is bolted to a flanged claniping ring v21 which encirclcs the rotary drum and surrounds a retaining ring 2,2 fixed to and carried by the drum on its outer periphery.Y

At the discharge end ot'- the drum an end flange 23 is bolted to the annular plate 24 and this end plate 24 is bolted to a clamp plate 25 Which encircle's and encloses the retaining ringr 26 on the exterior of the drum. .Suitable packing or gaskets'are utilized at the `the drum. An agitating compartment is interposed between adjoining grinding compartments, or a single agitatmg compartment may be utilized with a single grindingcompartment in the drum. These compartments as 27 and 28 are each formed by the use of pairs of spaced annular rings 29 secured at the inner side of the drum wall in suitable manner. The rings are disposed transversely of the drum and project toward 'ed material or dust.

the center or axis thereof a distance suflicient to provide a substantial barrier or wall to prevent displacement of the grinding balls from their respective grinding compartments.

,Longitudinally extending blades or litters 30' are spaced at'proper intervals about the inside of the drum between the pairs of rings 29 for the purpose of agitating the material and causing the suspension of the comminut- To assist in the passage of the material from the feeding or 'charging end ot the drum at the left in Figures l and 2, slots 31 areprovided in the spaced rings 29. These slots are of asize to permit the rings to confine the grinding balls in their compartments, but the slots are of sufficient size to readil permit passage therethrough of the materlal being reduced, as lime Jfor instance.

As before statedA the coarser material is ground or pulverized by the action of the rinding balls or other grinding agencies as 1t enters the rst compartment 5, and as the material successivel passes through the comartments 6 and 7 1t is successively reduced y the grinding action of the succeeding sets of balls 3 and 4. In the final grinding chainber 7 the material is pulverized or ground to an impalpable dust or desired linenes's. During its progress through the drum the material, lin addition to being reduced, is agitated,

and in all of the compartments thefincst dust is separated from the coal-ser material. After successive reductions, when the material reaches the final lgrinding compartment all the material in that compartmentiis reduced to the required fineness and the dust suspended Within the drum. Duc to this su'ccessive grinding and successive agitation imparted to the lime the entire charge of material fed to the druln is finely comminuted and suspended in the air swept mill tor pneumatic separation which is continuously occurring in all parts of the drum.I

j, In lusing the rotary drum, its peripheral speednts size, the size and number of grindingr and agitating compartments, and the sizes of the balls in the mill will be determined by the load carried and the character of the material to be reduced. While I have illustrated and referred to steel balls for the mill it will be appa-rent thatother agencies may be utilized as grinding mediums depending upon Vthe ,service rcqui red.

In the several grinding compartments the liner material 1s sifted from the coarser maonly by the agitating devices, but also by the falling and impact of the balls, and in this manner the coarser material inthe respective compartments is separated from the finer material (which remains in suspension) thus rendering the coarser material more readily accessible to the grinding action ofthe balls in the respective compartments.' As the impalpable dust is thus created in the severalA compartments it is continuously suspended in the drum and is subjected to the pneumatic action of the separator for conveying the dust lfrom the drum. V

The discharge end of the drum is provided with a ipe 32 which forms the intake for a y fan or lower within the casing 33, said fan being operated by a belt passing over the fan pulley 34 on its shaft 35 in Figure 1.

The pipe 32 forms the central intake for the fan blower which may be of suitable type for the purpose, and the discharge pipe 36 of the fan blower extends, in this instance, upwardly to *and has a tangential connection with the main dust collector 37 of the cyclone type. From the top of the main dust collector an au' supply pipe 38 is shown extending downwardly, an this supply pipe is connected to the air inlet-head 39 at the fe'edingor charging end of the drum. It will be apparent that currents of air are caused to sweep through v1terial in the respective compartments, not

the drum from the inlet head 39 through the outlet ipe 32 which forms the intake for the fan lower, conveying dust from the feed conveyer or screw and then successively from the succeeding compartments in the drum, and thence the dust is impelled by action of the fan blower through pipe 36 vto thecollector 37 for deposit therein.` l An' auxiliary'dust collector40 Ais connected by` a branch pipe 41 to the intake pipe 32 of the fan blower, and a valve or gate 42 in this pipe 41 controls and regulates the passage of4 a1r currents through pipe 41 to the fan blower.

Bymeans of a pipe 43 the auxiliary dust collector is connected to the air supply pipe of surplus airl between the air supply .pipe 38. andthe dust collector 4() and pipe 41.V

Within the auxiliary dust collector a baiile plate or baiile plates) 45 are'provided in the path of movement of air currents from theV pipe 43 for separation of dust fromV the air.

' Thus any dust thatmay escape from the main collector may be diverted to the auxiliary collector and there separated `from the air currents, or be returned to the intake of the blower. The surplus air froml the auxiliary collector may escape through outlet pipe 46, to the atmosphere.`

Bythis combination and arrangement of parts it will be appareiit thatlthe air supply l is furnished from an intake located between the closed drum and the fan blower, and the supply `is regulated b means of the valve or' gate 42. As the inta e pipe 41 has indirect communication with the discharge pipe 36 through lthe auxiliary :collector and vsurplus air' ipe 43 .whic is connected .with the top oft e main,V col ctor, the fan blowergvcan draw air through'the intake pipe 41to reducev dust from the drum.

`that the areas and capacity oftheV air supply',

PnSOll 0f air4 und fully consume the ust laden air. This exv.

the velocity or pressure of air 1n. theaii` supply pipe 38. By adjustment of thevalve 44 'i 1n plpe 43 the decrease of pressure or velocity 40- of ar in the air supply plpe 38 may be regulate i i It will be noted that the drum has an nnobstructed air sweptnterior-through'which the aix" currents pass by indirect exhaust of the fan blower for conveying the suspendedv It will also be noted pipe 38 and ofthe drum are materially greater than that of the dischargeK pipe 36` of the blower, thus providing means for decreasing the velocity of air currents between the main collector and thedrum or mill, to insure exrlnit the fan' blower to pension of air is also enhanced when the -valve v 44 is opened for use of the auxiliary'collector 40. The baille 'plates 45 of the auxiliary collector,it will be ap arent reduce the resist- I iary collector.

ance of air coming om 'the pipe 43, and the dust se arated from these alr currents falls to the -shaped settling chamber ofthe auxilfully described my invention,-

Havin thus what I c im as' new and desire to secure by i Letters Patent is- 1. In an airswept mill of the ball type havling a substantially unobstructed interior, a fan blower having its intake connected to one end ofthe mill, aidust collector connected to the exhaust of the fan blower, means for sup'- plying materia-l atone endof the mill, and an air supply pipe leading from the collector to the same end of the mill, whereby the material is conveyed to the intake of the fan by the velocity of the spent air supplied from the collector. 38, anda gate or valve 44 controls passage 2. A ball mill having asubstantially unobstructed air-swept interior, spaced compartments formed therein having alternating reducing and distributing means, a; fan

blower having its intake connected to one end i of the mill, a discharge pipe and a collector, an air supply pipe connecting said collector and the other end of the mill, and means in connection with the air supply pipe for decreasing the velocity of air currents between the collector and the mill.

successive -compartments having reducing means and intermediate compartments hav- 3. A'ball mill having a substantially unobstructed air swept interior comprising spaced Y ing distributers therein, a fan blower having its intake connected with one end of the mill, a dust collector connected with the discharge end of the blower, and an airsupply pipe con'- necting said collector with the other end of the mill. Y v

HARRY H. WATERMAN.

'lso 

